Spiro(indoline-2,2&#39;-2h&#39;-chromene)photochromic compounds

ABSTRACT

Photochromic compounds having the formula WHEREIN R1 is a member selected from the group consisting of an alkyl group, a substituted alkyl group, and an aralkyl group; wherein R2 and R3 each is a member selected from the group consisting of an alkyl group and a phenyl group; and, wherein R4 is a member selected from the group consisting of an alkyl group, a nitro group, a halogen atom, an aldehyde group, an alkoxyl group, a carboxyl group, and a carboxylic acid ester group; said alkyl group having from one to five carbon atoms are disclosed. The compounds are useful in recording media where their ability to change color on activation with ultraviolet light is advantageous.

ilnited States Patent [191 Ono et al.

[54] SPlRO(lNDOLlNE-2,2-2H- CHROMENE)PHOTOCHROMIC COMPOUNDS [73]Assignee: Fuji Photo Film Co. Ltd.,

Kanagawa, Japan [22] Filed: March 18,1970

[2i] Appl. No.: 20,761

[30] Foreign Application Priority Data March I8, I969 Japan ..44/206S7[52] U.S. Cl ..260/326.l1, 252/300 [51] Int. Cl. ..C07d 27/38 [58] Fieldof Search ..260/326.1l

[56] References Cited FOREIGN PATENTS OR APPLICATIONS l,394,l 63 2/1965France ..260/326.Il

Primary Examiner-Alex Mazel Assistant ExaminerJoseph A. NarcavageAtt0rneySughrue, Rothwell, Mion, Zinn and Macpeak 1 Jan. 30, 1973 [57]ABSTRACT Photochromic compounds having the formula l U \IY/\\%// I 2 R1R k/R3 wherein R is a member selected from the group consisting of analkyl group, a substituted alkyl group, and an aralkyl group; wherein Rand R each is a member selected from the group consisting of an alkylgroup and a phenyl group; and, wherein R is a member selected from thegroup consisting of an alkyl group, a nitro group, a halogen atom, analdehyde group, an alkoxyl group, a carboxyl group, and a carboxylicacid ester group; said alkyl group having from one to five carbon atomsare disclosed. The compounds are useful in recording media where theirability to change color on activation with ultraviolet light isadvantageous.

2 Claims, 1 Drawing Figure PATENTED AN Y 3.714.187

DENSITY 500 550 e60 660 (mp) INVENTOR HISATAKE 0N0 CHIAKI OSADA HARUMIKATSUYAMA ATTORNEYS SPIRO(INDOLINE-2,2'-2H'- CHROMENE)PHOTOCHROMICCOMPOUNDS BACKGROUND OF THE INVENTION 1. Field of the Invention richedwith ultraviolet rays or sunlight. That is to say,

such compounds have stable electronic configurations, in the absence ofactivation, with their own specific spectral characteristics (in manycases, the unactivated compound is colorless). However, when thecompound is irradiated with light of a specific wave length, the 2compound has a different absorption spectrum and is converted into acolored state. When the irradiation of the light is stopped, thecompound reverts to the original state (usually a colorless state).

Photochromism is observed in inorganic compounds and organic compoundsand further some compounds exhibit photochromism as liquids and othercompounds exhibit it as solids.

Compounds showing such photochromism have recently been investigatedactively and the fields of application have been enlarged. Among them,the utilization of such compounds as printing and photographic materialsis an appropriate example of effectively utilizing the features of thecompounds. More practically speaking, where a permanent recording ofinformation is unnecessary, by using in the printing material aphotochromic compound, as mentioned above, the information is recordedas an image for the necessary period of time. When the informationbecomes unnecessary, the image can be removed and the printing materialcan be used again.

Moreover, photochromic compounds can further be utilized as ultraviolet-absorbing glasses, curtains, display materials, and the like.

Although inorganic photochromic compounds have a high intensity and arepeating intensity to sunlight and ultraviolet rays, they have adisadvantage that the light response time thereof is long. Also,although conventional photochromic compounds have a short light responsetime and a high density, they have the disadvantages that the lightfastness thereof is weak and hence the repeating intensity is low. Thatis to say, compounds which are endowed with both advantages of theinorganic photochromic compounds and the organic photochromic compoundsare rare.

SUMMARY OF THE INVENTION Investigation directed to removing these faultsof 0 conventional photochromic compounds have resulted in the discoverythat photochromic compounds represented by the following general formulahave excellent properties:

wherein R represents an alkyl group, analkyl group substituted with asubstituent such as a cyano group, a hydroxyl group, a carboxyl group oran ethyl carboxylate or an aralkyl group; wherein R and R represent analkyl group or a phenyl group; and R represents an alkyl group, a nitrogroup, a halogen atom, an aldehyde group, an alkoxyl group, a carboxylgroup, or a carboxylic acid ester. Suitable alkyl groups have from oneto five carbon atoms. 7

DETAILED DESCRIPTION OF THE INVENTION That is, the compounds representedby the above general formula are colorless under ordinary conditions butwhen they are irradiated with ultraviolet light having wavelengths offrom 2,000 to 4,000 A, they are colored from blue to blue-purple andwhen they are placed in the dark, they retain the colored state for 10,20, 30 or more days.

On the other hand, when the colored compounds are exposed to visiblelight of from 4,000 to 6,400 A, the compounds are immediately convertedinto the originalcolorless state. Such coloring and discharging stepscan be applied repeatedly to these photochromic compounds.

A general method of preparing the compound of the present invention isexplained by the following reaction scheme:

The photochromic compounds of the present invention prepared as aboveare generally colorless or yellow compounds.

Each of the compounds mentioned above is dissolved in a solvent, atnormal temperature, such as benzene, toluene, carbon bisulfide,chloroform, ethyl acetate, methyl ethyl ketone, acetone, methyl alcohol,ethyl alcohol, acetonitrile, tetrahydrofuran, dioxane, B- oxymethylethyl ether, (methyl cellosolve), morpholine and ethylene glycol toprovide a colorless solution and when the solution is irradiated withultraviolet light, the solution changes to a blue color.

Moreover, the compound of the present invention is dissolved in an ethylacetate solution of polyvinyl acetate, an acetone solution of polymethylmethacrylate, an acetone solution of polyethyl methacrylate, adimethylformamide solution of cellulose acetate, or a benzene solutionof polystyrene, and the resultant solution is applied to a support suchas a baryta-coated paper, a synthetic resin sheet such as a celluloseacetate sheet or a polyethylene terephthalate sheet followed by dryingto provide a photochromic sheet. When the photochromic sheet thusprepared is irradiated with ultraviolet light, the sheet is colored blueto blue-purple and when the sheet thus colored is heated or exposed tovisible rays after the ultraviolet irradiation, the sheet becomescolorless again. This process can be repeated numerous times.

Practical examples of photochromic materials utilizing the abovementioned compounds of the present in vention are a photographic orprinting photochromic material prepared by applying the aforesaidcomposition containing the photochromic compound of this invention to ahigh molecular weight compound film or a baryta-coated paper, aninterior photochromic material prepared by applying the above-mentionedcomposition to a curtain or glass, a sun glass prepared by applying thecomposition to a lens or glass, and a photochromic material for use as afilter.

DESCRIPTION OF THE DRAWING The accompanying drawing is a graph showingthe change in the spectral characteristics of the compound having thefollowing structure (lit in the graph the absorption spectrum 1 of thecompound before irradiation with ultraviolet light and the absorptionspectrum 2 thereof after the irradiation of ultraviolet rays are shown.In the experiment, Toshiba SHL-100 was used as the light source andbenzene was used as the solvent.

EXAMPLE 1 In ml. of ethyl alcohol were dissolved 0.7 g of 5 ,5'-methylene-bis( 1,2,3 ,3-tetramethyl-indoleniumtosylate) and 0.4 g of5-nitro-salicylaldehyde and the resultant solution was refluxed for 30minutes.

The solution containing the reaction product was cooled to precipitatecrystals, which were recovered by filtration and washed with ethylalcohol. The crystals were recrystallized from a mixed solvent of ethylalcohol and acetone to provide 0.5 g. of the crystal of 5 ,5'-methylene-bis[ 6'-nitro-l ,3 ,3-trimethylspiro-(indoline-2,2'-2H'-chromene)] having a melting point of to 122 C.

EXAMPLE 2 In 30 ml. of ethyl alcohol were dissolved 1.4 g. of5,5-methylene-bis( l ,2,3,3-tetramethyl-indoleniumtosylate), 0.8 g. of3-methoxy-5-nitro-salicylaldehyde, and 0.5 g. of triethylamine and theresultant solution was refluxed for 20 minutes.

The product solution was cooled to precipitate crystals, which wererecovered by filtration and washed with ethyl alcohol. Then, thecrystals were recrystallized from a mixture of ethyl alcohol and acetoneto provide 1.1 g. of the faint green crystals of 5,5"-methylene-bis[6-nitro-8 '-methoxyl ,3,3-trimethylspiro-(indoline-2,2'-2H'-chromene)] having a melting pointof to 162 C.

EXAMPLE 3 In 30 ml. of ethyl alcohol were dissolved 1.4 g of 5 ,5-methylene-bis( 1,2,3 ,3-tetramethyl-indoleniumtosylate), 0.8 g. of3-formyl-salicylaldehyde, and 0.5 g of triethylamine, and the resultantsolution was refluxed for 20 minutes.

The product solution was cooled to precipitate crystals, which wererecovered by filtration and washed with ethyl alcohol. Thereafter, thecrystals were recrystallized from a mixture of ethyl alcohol and acetoneto provide 0.9 g of the faint brown crystals of 5 ,5 -methylene-bis[8-formyl-1 ,3 ,S-trimethylspiro- (indoline-2,2'-2I-I-chromene)] having amelting point of 159 to 162 C.

EXAMPLE 4 In 30 ml. of ethyl alcohol were dissolved 1.1 g. of 5 ,5'-methylene-bis( l-B -hydroxyethyl-2,3 ,3-trimethylindolenium-bromide),0.8 g. of 3-formyl-5-nitro-salicylaldehyde, and 0.4 g. of triethylamineand the solution prepared was refluxed for 20 minutes.

The product was cooled and the crystals precipitated were filtered andwashed with ethyl alcohol. Thereafter, the crystals were recrystallizedfrom a mixture of an alcohol and tetrahydrofuran to provide 1.] g. ofthe crystals of 5,5"-methylene-bis[6'-nitro-8-formyl-l-B-hydroxyethyl-3,3-dimethylspiro(indoline-2,2- 2H-chromene)] having amelting point above 300 C.

EXAMPLE 5 In 30 ml. of ethyl alcohol were dissolved 1.3 g. of5,5-methylene-bis(l-B -carboxyethyl-2,3,3-trimethylindolenium-bromide),0.8 g. of S-nitro-salicylaldehyde, and the solution thus prepared wasrefluxed for minutes.

The product solution was cooled to precipitate crystals, which wererecovered by filtration, washed with ethyl alcohol, and recrystallizedfrom a mixed solvent of ethyl alcohol and tetrahydrofuran to provide 0.9g. of the faint brown crystals of 5,5"-methylenebis]6'-nitro' l-B-carboxyethyl -3 ,3-dimethylspiro( indoline-2,2-2H'-chromene)].

EXAMPLE 6 ln ethyl alcohol were dissolved l.3 g. of 5,5- methylene-bis(l-B-carboxyethyl-2,3,3-trimethyl-indolenium-bromide). 1.2 g. of3,5-dibromo-salicylaldehyde, and 0.4 g. of triethylamine and theresultant solution was refluxed for 20 minutes.

The product solution was cooled to precipitate the crystals, which wererecovered by filtration, washed with ethyl alcohol and thenrecrystallized from a mixed solvent of ethyl alcohol and acetone toprovide 1.0 g. of the faint brown crystals of 5,5"-methylene-bis[6',8-dibromo-l-B-carboxyethyl-3,3-dimethylspiro(indoline- 2,2-2H-chromene)]having a melting point of 158 to 160 C.

EXAMPLE 7 EXAMPLE 8 A benzene solution, a toluene solution, and atetrahydrofuran solution of the compound prepared in Example I were allcolorless and when each of the solutions was irradiated with a mercurylamp, the solution was immediately colored blue and when the solutionwas placed in the dark, the color of the solution quickly becamecolorless.

Furthermore, a solution of 1 g. of the compound in 80 g. of a 15 percentpolystyrene-benzene solution was.

applied to a polyethylene terephthalate film of my. in thickness in adry thickness of 10 my. and dried.

When a photographic negative film. was closely placed on thephotochromic layer of the film thus prepared and they were exposed to amercury lamp, the exposed areas of the photochromic layer was coloredinto blue to provide a positive image. When the photochromic film wasplaced in the dark or heated, the image-bearing film was converted intothe original colorless film.

EXAMPLE 9 A benzene solution of the compound prepared in Example 2 wascolorless but when the solution was exposed to sunlight, it was coloredblue and when the solution was placed in the dark, the solution becamecolorless. The coloring and discharging procedure could be repeated 10,20, 30 times or more.

Then 1 g. of the compound was dissolved in g. ofa mixed solvent of 15percent polyvinyl acetate and ethyl acetate and the solution was appliedto a baryta-coated paper in a dry thickness of about 5 mp. Thelight-sensitive paper prepared hadthe same properties as those of thelight-sensitive film of Example 7, that is, when the light-sensitivepaper was irradiated with ultraviolet light, the photochromic layer wasimmediately colored dark blue and when it was placed in the dark, thelayer became colorless.

EXAMPLE l0 A tetrahydrofuran solution or a benzene solution of thecompound prepared in Example 3 was colorless but when the solution wasirradiated with ultraviolet light, the solution was immediately coloredblue and when the irradiation was terminated, the solution quicklybecame colorless.

EXAMPLE 1 l Each of the compounds prepared in Examples 4 to 7 wasapplied to a support in the same manner as in Example 8 and thelight-sensitive materials prepared had almost the same properties asthose of the light-sensitive material prepared in Example 8.

Besides the embodiments shown in the above examples, the compound of thepresent invention can be'applied to a support or cast together with asensitizer and a plasticizer.

What is claimed is:

l. A photochromic compound having the formula wherein R, is a memberselected from the group consisting of an alkyl group of from one to fivecarbon group consisting of an alkyl group of from one to five carbonatoms, a nitro group, a halogen atom, formyl and methoxy.

2. A photochromic compound of claim 1 wherein the alkoxy group of R is amethoxy group.

1. A photochromic compound having the formula wherein R1 is a memberselected from the group consisting of an alkyl group of from one to fivecarbon atoms, a substituted alkyl group of from one to five carbonatoms, whose substitutents are selected from the group consisting of ahydroxyl group, a carboxyl group, and an ethyl carboxylate group;wherein R2 and R3 each is a member selected from the group consisting ofan alkyl group of from one to five carbon atoms and phenyl; and, whereinR4 is a member selected from the group consisting of an alkyl group offrom one to five carbon atoms, a nitro group, a halogen atom, formyl andmethoxy.